Retinoic Acid and Retinoic Acid Receptors as Pleiotropic Modulators of the Immune System.

Vitamin A is a multifunctional vitamin implicated in a wide range of biological processes. Its control over the immune system and functions are perhaps the most pleiotropic not only for development but also for the functional fate of almost every cell involved in protective or regulatory adaptive or innate immunity. This is especially key at the intestinal border, where dietary vitamin A is first absorbed. Most effects of vitamin A are exerted by its metabolite, retinoic acid (RA), which through ligation of nuclear receptors controls transcriptional expression of RA target genes. In addition to this canonical function, RA and RA receptors (RARs), either as ligand-receptor or separately, play extranuclear, nongenomic roles that greatly expand the multiple mechanisms employed for their numerous and paradoxical functions that ultimately link environmental sensing with immune cell fate. This review discusses RA and RARs and their complex roles in innate and adaptive immunity.

Retinoic acid reduces the formation of, and acutely modulates, invertebrate electrical synapses.

Communication between cells in the nervous system is dependent on both chemical and electrical synapses. Factors that can affect chemical synapses have been well studied, but less is known about factors that influence electrical synapses. Retinoic acid, the vitamin A metabolite, is a known regulator of chemical synapses, but few studies have examined its capacity to regulate electrical synapses. In this study, we determine that retinoic acid is capable of rapidly altering the strength of electrical synapses in an isomer- and cell-dependent manner. Furthermore, we provide evidence that this acute effect might be independent of either the retinoid receptors or the activation of a protein kinase. In addition to the rapid modulatory effects of retinoic acid, we provide data to suggest that retinoic acid is also capable of regulating the formation of electrical synapses. Long-term exposure to both all-trans-retinoic acid or 9-cis-retinoic acid reduced the proportion of cell pairs forming electrical synapses, as well as reduced the strength of electrical synapses that did form. In summary, this study provides insights into the role that retinoids might play in both the formation and modulation of electrical synapses in the central nervous system.NEW & NOTEWORTHY Retinoids are known modulators of chemical synapses and mediate synaptic plasticity in the nervous system, but little is known of their effects on electrical synapses. Here, we show that retinoids selectively reduce electrical synapses in a cell- and isomer-dependent manner. This modulatory action on existing electrical synapses was rapid and nongenomic in nature. We also showed for the first time that longer retinoid exposures inhibit the formation of electrical synapses.

Mutation of aspartic acid 262 on estrogen receptor abrogates estradiol signaling pathway.

OBJECTIVE: ERα (estrogen receptor alpha) exerts nuclear genomic actions and membrane-initiated non-genomic effects. The mutation of aspartic acid into alanine in vitro revealed the critical role of aspartic acid 258 (corresponding to mouse amino acid site 262) of ERα for non-nuclear function. Our previous in vitro study revealed that this mutation blocked estrogen's non-genomic effects on vascular endothelial H2S release. Here, we studied the in vivo role of the aspartic acid 262 of ERα in the reproductive system and in the vascular tissue. APPROACH AND RESULTS: We generated a mouse model harboring a point mutation of the murine counterpart of this aspartic acid into alanine (ERαD262A). Our results showed that the ERαD262A females are fertile with standard hormonal serum levels, but the uterine development and responded with estrogen and follicular development are disrupted. In line with our previous study, we found that the rapid dilation of the aorta was abrogated in ERαD262A mice. In contrast to the previously reported R264-ERα mice, the classical estrogen genomic effector SP1/NOS3/AP1 and the nongenomic effectors p-eNOs, p-AKT, and p-ERK were disturbed in the ERαD262A aorta. Besides, the serum H2S concentration was decreased in ERαD262A mice. Together, ERαD262A mice showed compromised both genomic and non-genomic actions in response to E2. CONCLUSIONS: These data showed that aspartic acid 262 of ERα are important for both genomic and non-genomic effects of E2. Our data provide a theoretical basis for further selecting an effective non-genomic mouse model and provide a new direction for developing estrogen non-genomic effect inhibitors.

Non-Genomic Hallmarks of Aging-The Review.

Aging is a natural, gradual, and inevitable process associated with a series of changes at the molecular, cellular, and tissue levels that can lead to an increased risk of many diseases, including cancer. The most significant changes at the genomic level (DNA damage, telomere shortening, epigenetic changes) and non-genomic changes are referred to as hallmarks of aging. The hallmarks of aging and cancer are intertwined. Many studies have focused on genomic hallmarks, but non-genomic hallmarks are also important and may additionally cause genomic damage and increase the expression of genomic hallmarks. Understanding the non-genomic hallmarks of aging and cancer, and how they are intertwined, may lead to the development of approaches that could influence these hallmarks and thus function not only to slow aging but also to prevent cancer. In this review, we focus on non-genomic changes. We discuss cell senescence, disruption of proteostasis, deregualation of nutrient sensing, dysregulation of immune system function, intercellular communication, mitochondrial dysfunction, stem cell exhaustion and dysbiosis.

Cortisol Interaction with Aquaporin-2 Modulates Its Water Permeability: Perspectives for Non-Genomic Effects of Corticosteroids.

Aquaporins (AQPs) are water channels widely distributed in living organisms and involved in many pathophysiologies as well as in cell volume regulations (CVR). In the present study, based on the structural homology existing between mineralocorticoid receptors (MRs), glucocorticoid receptors (GRs), cholesterol consensus motif (CCM) and the extra-cellular vestibules of AQPs, we investigated the binding of corticosteroids on the AQP family through in silico molecular dynamics simulations of AQP2 interactions with cortisol. We propose, for the first time, a putative AQPs corticosteroid binding site (ACBS) and discussed its conservation through structural alignment. Corticosteroids can mediate non-genomic effects; nonetheless, the transduction pathways involved are still misunderstood. Moreover, a growing body of evidence is pointing toward the existence of a novel membrane receptor mediating part of these rapid corticosteroids' effects. Our results suggest that the naturally produced glucocorticoid cortisol inhibits channel water permeability. Based on these results, we propose a detailed description of a putative underlying molecular mechanism. In this process, we also bring new insights on the regulatory function of AQPs extra-cellular loops and on the role of ions in tuning the water permeability. Altogether, this work brings new insights into the non-genomic effects of corticosteroids through the proposition of AQPs as the membrane receptor of this family of regulatory molecules. This original result is the starting point for future investigations to define more in-depth and in vivo the validity of this functional model.

Cortisol promotes the cognitive regulation of high intensive emotions independent of timing.

Failures to cognitively downregulate negative emotions are a crucial risk factor for mental disorders. Previous studies provide evidence for a stress-induced improvement of cognitive emotion regulation possibly mediated via glucocorticoid actions. Cortisol can initialize immediate non-genomic as well as delayed genomic effects on cognitive control functioning, but its distinct effects on emotion regulation processes remain to be shown. Here, we sought to characterize time-dependent effects of oral cortisol administration on cognitive emotion regulation outcomes. We expected cortisol to improve emotion regulation success. Possible interactions with the delay between cortisol treatment and emotion regulation, strategy use and intensity of the emotional stimuli were examined. Eighty-five healthy men received either 10 mg hydrocortisone or a placebo in a double-blind, randomized design 30 or 90 min prior to an emotion regulation paradigm, in which they were asked to downregulate their emotional responses towards low and high intensive negative pictures via reappraisal or distraction. Affective ratings and pupil dilation served as outcome measures. Reduced arousal, enhanced valence ratings as well as increases in pupil dilations indexing the cognitive regulatory effort indicated successful downregulation of negative emotions evoked by high intensive but not low intensive negative pictures. Cortisol significantly reduced arousal ratings when downregulating high intensive negative emotions via distraction and (at a trend level) via reappraisal, independent of timing, demonstrating a beneficial effect of cortisol on subjective regulatory outcomes. Taken together, this study provides initial evidence suggesting that cortisol promotes the cognitive control of high intensive negative emotions both, 30 and 90 min after treatment.

Estrogen receptor variant ER-α36 facilitates estrogen signaling via EGFR in glioblastoma.

Glioblastoma (GBM) is a deadly and common primary brain tumor. Poor prognosis is linked to high proliferation and cell heterogeneity. Sex differences may play a role in patient outcome. Previous studies showed that ER-α36, a variant of the estrogen receptor (ER), mediated non-genomic estrogen signaling and is highly expressed in many ER-negative malignant tumors. ER-α36 also associates with epidermal growth factor receptor (EGFR). The primary purpose of this study is to investigate the cross talk between ER-α36 and EGFR in estrogen-mediated GBM cell proliferation. Here, we showed that ER-α36 was highly expressed and confirmed that ER-α36 co-labels with EGFR in human GBM samples using immunohistochemical techniques. We also investigated the mechanisms of estrogen-induced proliferation in ER-α-negative cell lines. We found that GBM cells showed varying responsive to mitogenic estrogen signaling which correlated with ER-α36 expression, and knockdown of ER-α36 diminished the response. Exposure to estrogen also caused upregulation of cyclin protein expression in vitro. We also found that low concentration of estrogen promoted SRC-Y-416 and inhibited SRC-Y-527 phosphorylation, corresponding with activated SRC signaling. Inhibiting SRC or EGFR abolished estrogen-induced mitogenic signaling, including cyclin expression and MAPK phosphorylation. Cumulatively, our results demonstrate that ER-α36 promotes non-genomic estrogen signaling via the EGFR/SRC/MAPK pathway in GBM. This may be important for the treatment of ER-α-negative GBMs that retain high level of ER-α36, since estrogen may be a viable therapeutic target for these patients.

17ß-Estradiol nongenomically induces vasodilation is enhanced by promoting phosphorylation of endophilin A2.

ObjectiveA previous study found that the tyrosine phosphorylation of endophilin A2 (Endo II) was responsible for increase surface expression of MT1-MMP and ECM degradation; however, there is little information about whether Endo II could influence membrane estrogen receptors (mERs) and its functions.Materials and methodsIn the present study, Human umbilical vein endothelial cells (HUVECs) were treated with E2, PPT, DPN, ICI 182780, Endo siRNA or negative control siRNA, and the biological behavior of the treated cells was observed. The mice were randomly divided into AAV-control-shRNA + Ach, AAV-Endo II-shRNA + Ach, AAV-control-shRNA + E2, AAV-Endo II-shRNA + E2 groups and the thoracic aorta were isolated, cut into 2-mm rings, then the wall tension was detected.ResultsWe found that 17ß-Estradiol (E2) enhanced mERα protein level, which was further increased after knocking down Endo II, the mechanism maybe involved in E2-induced tyrosine phosphorylation of Endo II. In addition, we also observed that Endo II blocked the activation of Akt, ERK1/2 and eNOS signaling in HUVECs treated with E2. E2 induced vasodilation was significantly increased by silencing of Endo II expression.ConclusionOur study provided a sound basis to selective modulate Endo II for E2's nongenomic pathway, which can be benefit for cardiovascular system.

A New Perspective on Thyroid Hormones: Crosstalk with Reproductive Hormones in Females.

Accumulating evidence has shown that thyroid hormones (THs) are vital for female reproductive system homeostasis. THs regulate the reproductive functions through thyroid hormone receptors (THRs)-mediated genomic- and integrin-receptor-associated nongenomic mechanisms, depending on TH ligand status and DNA level, as well as transcription and extra-nuclear signaling transduction activities. These processes involve the binding of THs to intracellular THRs and steroid hormone receptors or membrane receptors and the recruitment of hormone-response elements. In addition, THs and other reproductive hormones can activate common signaling pathways due to their structural similarity and shared DNA consensus sequences among thyroid, peptide, and protein hormones and their receptors, thus constituting a complex and reciprocal interaction network. Moreover, THs not only indirectly affect the synthesis, secretion, and action of reproductive hormones, but are also regulated by these hormones at the same time. This crosstalk may be one of the pivotal factors regulating female reproductive behavior and hormone-related diseases, including tumors. Elucidating the interaction mechanism among the aforementioned hormones will contribute to apprehending the etiology of female reproductive diseases, shedding new light on the treatment of gynecological disorders.

The Impact of Corticosteroids on Human Airway Smooth Muscle Contractility and Airway Hyperresponsiveness: A Systematic Review.

Classically, the effects elicited by corticosteroids (CS) are mediated by the binding and activation of cytosolic glucocorticoid receptors (GR). However, several of the non-genomic effects of CS seem to be mediated by putative non-classic membrane receptors characterized by pharmacological properties that are different from those of classic cytosolic GR. Since pre-clinical findings suggest that inhaled CS (ICS) may also regulate the bronchial contractile tone via putative CS membrane-associate receptors, the aim of this review was to systematically report and discuss the impact of CS on human airway smooth muscle (ASM) contractility and airway hyperresponsiveness (AHR). Current evidence indicates that CS have significant genomic/non-genomic beneficial effects on human ASM contractility and AHR, regardless of their anti-inflammatory effects. CS are effective in reducing either the expression, synthesis or activity of α-actin, CD38, inositol phosphate, myosin light chain kinase, and ras homolog family member A in response to several pro-contractile stimuli; overall these effects are mediated by the genomic action of CS. Moreover, CS elicited a strong bronchorelaxant effect via the rapid activation of the Gsα-cyclic-adenosine-monophosphate-protein-kinase-A pathway in hyperresponsive airways. The possibility of modulating the dose of the ICS in a triple ICS/long-acting ß2-adrenoceptor agonist/long-acting muscarinic antagonist fixed-dose combination supports the use of a Triple MAintenance and Reliever Therapy (TriMART) in those asthmatic patients at Step 3-5 who may benefit from a sustained bronchodilation and have been suffering from an increased parasympathetic tone.

Extra-genomic instructive influences in morphogenesis: A review of external signals that regulate growth and form.

Embryonic development and regeneration accomplish a remarkable feat: individual cells work together to create or repair complex anatomical structures. What is the source of the instructive signals that specify these invariant and robust organ-level outcomes? The most frequently studied source of morphogenetic control is the host genome and its transcriptional circuits. However, it is now apparent that significant information affecting patterning also arrives from outside of the body. Both biotic and physical factors, including temperature and various molecular signals emanating from pathogens, commensals, and conspecific organisms, affect developmental outcomes. Here, we review examples in which anatomical patterning decisions are strongly impacted by lateral signals that originate from outside of the zygotic genome. The endogenous pathways targeted by these influences often show transgenerational effects, enabling them to shape the evolution of anatomies even faster than traditional Baldwin-type assimilation. We also discuss recent advances in the biophysics of morphogenetic controls and speculate on additional sources of important patterning information which could be exploited to better understand the evolution of bodies and to design novel approaches for regenerative medicine.

Selective Inhibition of Genomic and Non-Genomic Effects of Thyroid Hormone Regulates Muscle Cell Differentiation and Metabolic Behavior.

Thyroid hormones (THs) are key regulators of different biological processes. Their action involves genomic and non-genomic mechanisms, which together mediate the final effects of TH in target tissues. However, the proportion of the two processes and their contribution to the TH-mediated effects are still poorly understood. Skeletal muscle is a classical target tissue for TH, which regulates muscle strength and contraction, as well as energetic metabolism of myofibers. Here we address the different contribution of genomic and non-genomic action of TH in skeletal muscle cells by specifically silencing the deiodinase Dio2 or the ß3-Integrin expression via CRISPR/Cas9 technology. We found that myoblast proliferation is inversely regulated by integrin signal and the D2-dependent TH activation. Similarly, inhibition of the nuclear receptor action reduced myoblast proliferation, confirming that genomic action of TH attenuates proliferative rates. Contrarily, genomic and non-genomic signals promote muscle differentiation and the regulation of the redox state. Taken together, our data reveal that integration of genomic and non-genomic signal pathways finely regulates skeletal muscle physiology. These findings not only contribute to the understanding of the mechanisms involved in TH modulation of muscle physiology but also add insight into the interplay between different mechanisms of action of TH in muscle cells.

Conflicting Nongenomic Effects of Progesterone in the Myometrium of Pregnant Rats.

Recently, it has been suggested that progesterone affects the contractile activity of pregnant myometrium via nongenomic pathways; therefore, we aimed to clarify whether progesterone causes and/or inhibits pregnant myometrial contractions via nongenomic pathways. Our in vitro experiments using myometrial strips obtained from rats at 20 days of gestation revealed that progesterone caused myometrial contractions in a concentration- and time-dependent manner at concentrations up to 5 × 10-7 M; however, this effect decreased at concentrations higher than 5 × 10-5 M. Similarly, progesterone enhanced oxytocin-induced contractions up to 5 × 10-7 M and inhibited contractions at concentrations higher than 5 × 10-5 M. Conversely, progesterone did not enhance high-KCl-induced contractions but inhibited contractions in a concentration- and time-dependent manner at concentrations higher than 5 × 10-7 M. We also found that RU486 did not affect progesterone-induced contractions or the progesterone-induced inhibition of high-KCl-induced contractions; however, progesterone-induced contractions were blocked by calcium-free phosphate saline solution, verapamil, and nifedipine. In addition, FPL64176, an activator of L-type voltage-dependent calcium channels, enhanced high-KCl-induced contractions and rescued the decrease in high-KCl-induced contractions caused by progesterone. Together, these results suggest that progesterone exerts conflicting nongenomic effects on the contractions of pregnant myometrium via putative L-type voltage-dependent calcium channels.

Genomic and Non-Genomic Actions of Glucocorticoids on Adipose Tissue Lipid Metabolism.

Glucocorticoids (GCs) are hormones that aid the body under stress by regulating glucose and free fatty acids. GCs maintain energy homeostasis in multiple tissues, including those in the liver and skeletal muscle, white adipose tissue (WAT), and brown adipose tissue (BAT). WAT stores energy as triglycerides, while BAT uses fatty acids for heat generation. The multiple genomic and non-genomic pathways in GC signaling vary with exposure duration, location (adipose tissue depot), and species. Genomic effects occur directly through the cytosolic GC receptor (GR), regulating the expression of proteins related to lipid metabolism, such as ATGL and HSL. Non-genomic effects act through mechanisms often independent of the cytosolic GR and happen shortly after GC exposure. Studying the effects of GCs on adipose tissue breakdown and generation (lipolysis and adipogenesis) leads to insights for treatment of adipose-related diseases, such as obesity, coronary disease, and cancer, but has led to controversy among researchers, largely due to the complexity of the process. This paper reviews the recent literature on the genomic and non-genomic effects of GCs on WAT and BAT lipolysis and proposes research to address the many gaps in knowledge related to GC activity and its effects on disease.

The Intriguing Thyroid Hormones-Lung Cancer Association as Exemplification of the Thyroid Hormones-Cancer Association: Three Decades of Evolving Research.

Exemplifying the long-pursued thyroid hormones (TH)-cancer association, the TH-lung cancer association is a compelling, yet elusive, issue. The present narrative review provides background knowledge on the molecular aspects of TH actions, with focus on the contribution of TH to hallmarks of cancer. Then, it provides a comprehensive overview of data pertinent to the TH-lung cancer association garnered over the last three decades and identifies obstacles that need to be overcome to enable harnessing this association in the clinical setting. TH contribute to all hallmarks of cancer through integration of diverse actions, currently classified according to molecular background. Despite the increasingly recognized implication of TH in lung cancer, three pending queries need to be resolved to empower a tailored approach: (1) How to stratify patients with TH-sensitive lung tumors? (2) How is determined whether TH promote or inhibit lung cancer progression? (3) How to mimic the antitumor and/or abrogate the tumor-promoting TH actions in lung cancer? To address these queries, research should prioritize the elucidation of the crosstalk between TH signaling and oncogenic signaling implicated in lung cancer initiation and progression, and the development of efficient, safe, and feasible strategies leveraging this crosstalk in therapeutics.

Main Factors Involved in Thyroid Hormone Action.

The thyroid hormone receptors are the mediators of a multitude of actions by the thyroid hormones in cells. Most thyroid hormone activities require interaction with nuclear receptors to bind DNA and regulate the expression of target genes. In addition to genomic regulation, thyroid hormones function via activation of specific cytosolic pathways, bypassing interaction with nuclear DNA. In the present work, we reviewed the most recent literature on the characteristics and roles of different factors involved in thyroid hormone function in particular, we discuss the genomic activity of thyroid hormone receptors in the nucleus and the functions of different thyroid hormone receptor isoforms in the cytosol. Furthermore, we describe the integrin αvß3-mediated thyroid hormone signaling pathway and its rapid nongenomic action in the cell. We furthermore reviewed the thyroid hormone transporters enabling the uptake of thyroid hormones in the cell, and we also include a paragraph on the proteins that mediate thyroid receptors' shuttling from the nucleus to the cytosol.

Binding of Androgen- and Estrogen-Like Flavonoids to Their Cognate (Non)Nuclear Receptors: A Comparison by Computational Prediction.

Flavonoids are plant bioactives that are recognized as hormone-like polyphenols because of their similarity to the endogenous sex steroids 17ß-estradiol and testosterone, and to their estrogen- and androgen-like activity. Most efforts to verify flavonoid binding to nuclear receptors (NRs) and explain their action have been focused on ERα, while less attention has been paid to other nuclear and non-nuclear membrane androgen and estrogen receptors. Here, we investigate six flavonoids (apigenin, genistein, luteolin, naringenin, quercetin, and resveratrol) that are widely present in fruits and vegetables, and often used as replacement therapy in menopause. We performed comparative computational docking simulations to predict their capability of binding nuclear receptors ERα, ERß, ERRß, ERRγ, androgen receptor (AR), and its variant ART877A and membrane receptors for androgens, i.e., ZIP9, GPRC6A, OXER1, TRPM8, and estrogens, i.e., G Protein-Coupled Estrogen Receptor (GPER). In agreement with data reported in literature, our results suggest that these flavonoids show a relevant degree of complementarity with both estrogen and androgen NR binding sites, likely triggering genomic-mediated effects. It is noteworthy that reliable protein-ligand complexes and estimated interaction energies were also obtained for some suggested estrogen and androgen membrane receptors, indicating that flavonoids could also exert non-genomic actions. Further investigations are needed to clarify flavonoid multiple genomic and non-genomic effects. Caution in their administration could be necessary, until the safe assumption of these natural molecules that are largely present in food is assured.

Steroid-induced rapid recovery from respiratory dysfunction in a patient with myasthenia gravis after spinal anesthesia.

We report an 83-year-old man with myasthenia gravis (MG) who developed respiratory depression after spinal anesthesia for transurethral laser enucleation of the prostate. He became less responsive after complained of dyspnea, with a decrease of SpO2 to 83% approximately 13 min after intrathecal administration of 0.5% isobaric bupivacaine 3 ml. With a diagnosis of exacerbation of MG, hydrocortisone 100 mg was administered, following which both consciousness and spontaneous respiration rapidly improved. Cold sense was observed below the C4 dermatome. We provided general anesthesia without using muscle relaxants until disappearance of the effect of spinal anesthesia. Surgery completed uneventfully and confirmed wearing off the local anesthetics effect. He was discharged without respiratory problems on postoperative 3 day.

Mitochondrial localization, import, and mitochondrial function of the androgen receptor.

Nuclear localization of androgen receptor (AR) directs transcriptional regulation of a host of genes, referred to as genomic signaling. Additionally, nonnuclear or nongenomic activities of the AR have long been described, but understanding of these activities remains elusive. Here, we report that AR is imported into and localizes to mitochondria and has a novel role in regulating multiple mitochondrial processes. Employing complementary experimental approaches of AR knockdown in AR-expressing cells and ectopic AR expression in AR-deficient cells, we demonstrate an inverse relationship between AR expression and mitochondrial DNA (mtDNA) content and transcription factor A, mitochondrial (TFAM), a regulator of mtDNA content. We show that AR localizes to mitochondria in prostate tissues and cell lines and is imported into mitochondria in vitro We also found that AR contains a 36-amino-acid-long mitochondrial localization sequence (MLS) capable of targeting a passenger protein (GFP) to the mitochondria and that deletion of the MLS abolishes the import of AR into the mitochondria. Ectopic AR expression reduced the expression of oxidative phosphorylation (OXPHOS) subunits. Interestingly, AR also controlled translation of mtDNA-encoded genes by regulating expression of multiple nuclear DNA-encoded mitochondrial ribosomal proteins. Consistent with these observations, OXPHOS supercomplexes were destabilized, and OXPHOS enzymatic activities were reduced in AR-expressing cells and restored upon AR knockdown. Moreover, mitochondrial impairment induced AR expression and increased its translocation into mitochondria. We conclude that AR localizes to mitochondria, where it controls multiple mitochondrial functions and mitonuclear communication. Our studies also suggest that mitochondria are novel players in nongenomic activities of AR.

17ß-Estradiol nongenomically induces vascular endothelial H2S release by promoting phosphorylation of cystathionine γ-lyase.

Estrogen exerts its cardiovascular protective role at least in part by regulating endothelial hydrogen sulfide (H2S) release, but the underlying mechanisms remain to be fully elucidated. Estrogen exerts genomic effects, i.e. those involving direct binding of the estrogen receptor (ER) to gene promoters in the nucleus, and nongenomic effects, mediated by interactions of the ER with other proteins. Here, using human umbilical vein endothelial cells (HUVECs), immunological detection, MS-based analyses, and cGMP and H2S assays, we show that 17ß-estradiol (E2) rapidly enhances endothelial H2S release in a nongenomic manner. We found that E2 induces phosphorylation of cystathionine γ-lyase (CSE), the key enzyme in vascular endothelial H2S generation. Mechanistically, E2 enhanced the interaction of membrane ERα with the Gα subunit Gαi-2/3, which then transactivated particulate guanylate cyclase-A (pGC-A) to produce cGMP, thereby activating protein kinase G type I (PKG-I). We also found that PKG-Iß, but not PKG-Iα, interacts with CSE, leading to its phosphorylation, and rapidly induces endothelial H2S release. Furthermore, we report that silencing of either CSE or pGC-A in mice attenuates E2-induced aorta vasodilation. These results provide detailed mechanistic insights into estrogen's nongenomic effects on vascular endothelial H2S release and advance our current understanding of the protective activities of estrogen in the cardiovascular system.